The present invention relates to a tooth implant, having a conical fastening portion with a thread which becomes progressively wider from the rounded apical end. A tooth implant of that kind is known from U.S. Pat. No. 6,402,515. The single, progressive thread disclosed therein is provided to improve adhesion of the tooth implant in the bone.
There is known from US 2004/101808 A1 an implant system having a double anti-rotational structure between the implant and the abutment. In that case, the implant has a conical shape with rounded apical end.
US 2004/219488 A1 discloses what is referred to therein as a micro-thread which follows on from a two-start thread. That micro-thread contains a number of small helical grooves.
There is known from WO 2004/098442 a screw-in tooth implant in which groove-like recesses are stamped into a relatively coarse thread, which recesses extend in the direction of the turns of the thread and produce there a so-called micro-thread in order to increase the area of contact between the tooth implant and bone tissue. The threaded pin itself is substantially cylindrical and the thread is not progressive.
U.S. Pat. No. 5,403,136 discloses a tooth implant with screw thread, which towards the cervical end has a thread with a decreasing pitch. The main part of the pin is cylindrical and is plane at the apical end.
US-A1-2004/0006346 discloses a tooth implant pin that is substantially cylindrical and has a plane apical end. The pin has two different threads, a relatively coarse single thread and then a so-called micro-thread which in this case is in the form of a triple thread.
WO 2004/103202 discloses, like the first-mentioned U.S. patent, a conical tooth implant with a progressive thread.